Mozilla launched the beta version of Firefox 5,the 
final version will be released officially next june 21. Firefox 5 beta offer new feature of the Channel Switcher that lets users switch from the development version to a version that is more stable through the dialog box.
But when tested, Firefox Channel Switcher only works when user are using it from channel beta to channel alpha owned aurora, meanwhile, if the user switched to Aurora through the Firefox Channel Switcher this will remove the beta.
Firefox 5 beta also display the feedback button located in aurora and designed to encourerage users to report bugs as well as give their opinions on development version of these browsers.
Firefox 5 Beta can be download free for Windows, Linux, Mac for old version please click here.